Thursday, June 30, 2016

A central topic for conservation science is evaluating how human activities influence global species diversity. Humanity exacerbates extinction rates. But by what mechanisms does humanity drive the emergence of new species? We review human-mediated speciation, compare speciation and known extinctions, and discuss the challenges of using net species diversity as a conservation objective. Humans drive rapid evolution through relocation, domestication, hunting and novel ecosystem creation—and emerging technologies could eventually provide additional mechanisms. The number of species relocated, domesticated and hunted during the Holocene is of comparable magnitude to the number of observed extinctions. While instances of human-mediated speciation are known, the overall effect these mechanisms have upon speciation rates has not yet been quantified. We also explore the importance of anthropogenic influence upon divergence in microorganisms. Even if human activities resulted in no net loss of species diversity by balancing speciation and extinction rates, this would probably be deemed unacceptable. We discuss why, based upon ‘no net loss’ conservation literature—considering phylogenetic diversity and other metrics, risk aversion, taboo trade-offs and spatial heterogeneity. We conclude that evaluating speciation alongside extinction could result in more nuanced understanding of biosphere trends, clarifying what it is we actually value about biodiversity.

A low-temperature flow tube and ultra-high vacuum apparatus were used to explore the uptake and heterogeneous chemistry of acetylene (C2H2) on cosmic dust analogues over the temperature range encountered in Titan's atmosphere below 600 km. The uptake coefficient, γ, was measured at 181 K to be (1.6 ± 0.4) × 10-4, (1.9 ± 0.4) × 10−4 and (1.5 ± 0.4) × 10−4 for the uptake of C2H2 on Mg2SiO4, MgFeSiO4 and Fe2SiO4, respectively, indicating that γ is independent of Mg or Fe active sites. The uptake of C2H2 was also measured on SiO2 and SiC as analogues for meteoric smoke particles in Titan's atmosphere, but was found to be below the detection limit (γ < 6 × 10−8 and < 4 × 10-7, respectively). The rate of cyclo-trimerization of C2H2 to C6H6 was found to be 2.6 × 10-5 exp(-741/T) s−1, with an uncertainty ranging from ± 27 % at 115 K to ± 49 % at 181 K. A chemical ablation model was used to show that the bulk of cosmic dust particles (radius 0.02–10 µm) entering Titan's atmosphere do not ablate (< 1% mass loss through sputtering), thereby providing a significant surface for heterogeneous chemistry. A 1D model of dust sedimentation shows that the production of C6H6via uptake of C2H2 on cosmic dust, followed by cyclo-trimerization and desorption, is probably competitive with gas-phase production of C6H6 between 80 and 120 km.

The asteroid belt hides lots of mysteries of the solar system’s past, but perhaps no place holds more mysteries than Ceres. It’s an oddball place — a dwarf planet in the midst of our solar system’s belt of smaller debris. And it’s an ancient world possibly left over from the era when the planets first came together.

The Chinese conducted the maiden launch of the Long March 7 rocket on Saturday. The launch took place at 12:00 UTC, which also involved the inauguration of is new Wenchang Space Launch Center, located at the Hainan Island. The main payload for this mission was a scaled-down version of a next generation crew vehicle that was successfully recovered in Inner Mongolia after a short orbital flight.

The US Army is turning to foreign systems for an interim solution for advanced protection for its combat vehicles against rocket-propelled grenades, anti-tank guided missiles and other threats.

The service’s effort to rapidly integrate already developed solutions is heating up this summer as the Army tests out what will likely be four different solutions on M1 Abrams tanks, Bradley Fighting Vehicles and Stryker combat vehicles.

Such threats like RPGs aren’t just resident in one theater, but are problems world-wide for armored combat vehicles and it’s only growing, particularly in the Central and European Command area of operations.

Partly spurring the effort is the possibility that Russia is ahead of the US Army when it comes to armor protection as evidenced by the reported survivability of its tanks when up against Ukrainian anti-tank and anti-armor weapons in the ongoing conflict along Ukraine’s border with Russia.

Drivers (or riders?) prefer self driving cars that will prioritize their lives over others in an accident. Duh. However, equally duh that the car will pick the least lives to be lost, not because its the most ethical stance, but because that will cost the manufacturer the least when settling with victims.

In Europe, there is a draft plan to declare robots to be 'electronic persons'
and require companies to pay for social security for each bot. This is
weird, but potentially clever way of doing a robot tax, but at the same
time paving the way for law for when and if computers become sentient.

Researchers from the University of Oxford have revealed that the genetic ancestries of many of sub-Saharan Africa's populations are the result of historical DNA mixing events, known as admixture, within the last 4,000 years.

Their study, to be published in the journal eLife, uncovers signatures of these admixture events through a large analysis of DNA from populations across the continent. The discovery provides a foundation for the recent genetic history of the continent, which could aid future studies of non-communicable and infectious diseases, such as malaria.

While admixture has been demonstrated in other regions of the world, the new analysis has allowed the team to characterise sub-Saharan Africa's mixing events in an unprecedented level of detail.

"As Africa has few written records of its history, it is somewhat unknown what important movements of people generated the populations in the continent today," says lead author George Busby, Statistical Geneticist at the Wellcome Trust Centre for Human Genetics.

"Looking at and comparing the differences in the genomes of people alive today can help us better understand and reconstruct the historical interactions that brought their ancestors together."

Though mammals adapted on land, a new study by Maria Chikina and Nathan Clark has shown that during three major independent evolutionary events, a number of mammals harkened back to the sea.

For the manatee, walrus, dolphin, and killer whale, the return to the sea involved many evolutionary trade-offs amongst hundreds of genes: a general loss of the number of sensory genes for smell and taste, new functions for genes forming skin and connective tissue, and genes involved in muscle structure and metabolism.

In a massive undertaking, they used 59 placental mammal genomes to calculate the relative rates of evolution for all branches in 18,049 gene trees. To hone in identifying key genes, they used a new approach: rather than catalog single genetic mutations from genome-wide studies, or look for candidate genes in key pathways, or catalog single amino acid changes at the protein level, they calculated a genome-wide average rate of evolution across all species. Then, they determined whether sea mammals had put the evolutionary gas pedal or brake on compared to the average rate. In the next step, they employed these relative rates to identify those genes that may have independently shifted to higher (or lower) rates for five marine species - bottlenose dolphin, orca, walrus, Weddell seal, and West Indian manatee. "By exploiting the diversity within mammals, we stand to learn much about our own genetics and physiology," said Clark. "Our new approach is poised to reveal the evolutionary adaptations for countless other environments, from the sea, high altitudes, the desert, or even underground."

They identified hundreds of genes that revealed three main evolutionary themes - a burst of adaptation, followed by relaxation, and additional constraint -in response to the marine environment.

There have been several mass extinctions in the history of Earth with adverse consequences for the environment. Researchers from the University of Zurich have now uncovered another disaster that took place around 250 million years ago and completely changed the prevalent vegetation during the Lower Triassic.

There have been several mass extinctions in the history of Earth. One of the largest known disasters occurred around 252 million years ago at the boundary between the Permian and the Triassic. Almost all sea-dwelling species and two thirds of all reptiles and amphibians died out. Although there were also brief declines in diversity in the plant world, they recovered in the space of a few thousand years, which meant that similar conditions to before prevailed again.

Sulfur isotopic anomalies (∆33S and ∆36S) have been used to trace the redox evolution of the Precambrian atmosphere and to document the photochemistry and transport properties of the modern atmosphere. Recently, it was shown that modern sulfate aerosols formed in an oxidizing atmosphere can display important isotopic anomalies, thus questioning the significance of Archean sulfate deposits. Here, we performed in situ 4S-isotope measurements of 3.2- and 3.5-billion-year (Ga)-old sulfates. This in situ approach allows us to investigate the diversity of Archean sulfate texture and mineralogy with unprecedented resolution and from then on to deconvolute the ocean and atmosphere Archean sulfur cycle. A striking feature of our data is a bimodal distribution of δ34S values at ∼+5‰ and +9‰, which is matched by modern sulfate aerosols. The peak at +5‰ represents barite of different ages and host-rock lithology showing a wide range of ∆33S between −1.77‰ and +0.24‰. These barites are interpreted as primary volcanic emissions formed by SO2 photochemical processes with variable contribution of carbonyl sulfide (OCS) shielding in an evolving volcanic plume. The δ34S peak at +9‰ is associated with non–33S-anomalous barites displaying negative ∆36S values, which are best interpreted as volcanic sulfate aerosols formed from OCS photolysis. Our findings confirm the occurrence of a volcanic photochemical pathway specific to the early reduced atmosphere but identify variability within the Archean sulfate isotope record that suggests persistence throughout Earth history of photochemical reactions characteristic of the present-day stratosphere.

Those who go to a masked ball consciously slip into a different role, in order to avoid being recognized so quickly. Insects were already doing something very similar in the Cretaceous: They cloaked themselves in pieces of plants, grains of sand, or the remains of their prey, in order, for example, to be invisible to predators. An international research team, with participation from the University of Bonn, has now investigated such "invisibility cloaks" encased in amber. The custom-tailored "costumes" also permit conclusions about the habitat at the time. The results have now been published in the journal "Science Advances".

The larva of the lacewing attacks a pseudoscorpion and uses its powerful mouthparts to suck it dry. The larva then puts the remains of the dead prey on its back. The outlines of the lacewing are now unrecognizable. It looks more like a dead pseudoscorpion. This camouflage protects the lacewing against being recognized by predators and at the same makes it easier to hunt its own prey. "With this 'disguise', the lacewing larva pretends to be someone completely different", says Prof. Dr. Jes Rust of the Steinmann-Institute of the University of Bonn. "Using the pieces of its prey, it even takes on the smell of the pseudoscorpion".

The scene plays out in the Cretaceous and is recorded as a "snapshot" in amber. A research team under Dr. Bo Wang of the State Key Laboratory of Paleobiology and Stratigraphy in Nanjing (China) worked together with paleontologists from the University of Bonn and other scientists from China, USA, France, and England to examine a total of 35 insects preserved in amber. With the aid of grains of sand, plant residue, wood fibers, dust, or even the lifeless shells of their victims, the larvae achieved camouflage to perfection. The amber samples come from Myanmar, France, and Lebanon.

The potential evolutionary link between hairs in mammals, feathers in birds and scales in reptiles has been debated for decades. Today, researchers of the University of Geneva (UNIGE) and the SIB Swiss Institute of Bioinformatics, Switzerland, demonstrate that all these skin appendages are homologous: they share a common ancestry. On the basis of new analyses of embryonic development, the Swiss biologists evidenced molecular and micro-anatomical signatures that are identical between hairs, feathers and scales at their early developmental stages. These new observations, published today in Science Advances, indicate that the three structures evolved from their common reptilian ancestor.

Mammalian hairs and avian feathers develop from a similar primordial structure called a 'placode': a local thickening of the epidermis with columnar cells that reduce their rate of proliferation and express very specific genes. This observation has puzzled evolutionary and developmental biologists for many years because birds and mammals are not sister groups: they evolved from different reptilian lineages. According to previous studies, reptiles' scales however do not develop from an anatomical placode. This would imply that birds and mammals have independently 'invented' placodes during their evolution.

Carbonado is a porous polycrystalline diamond rock found in central African and Brazilian placer deposits. It contains unsupported radiogenic isotopes of He, Ne, Kr, Xe, and Pb. Here we show that these, and the radiation-related defects introduced to the diamond structure, are a result of uranium precipitation, with no isotopic or spectroscopic evidence of Th enrichment. The daughter products are unsupported due to Proterozoic U remobilization. Combining existing carbonado Pb isotope data with recent studies of the geochronology of the tectonic evolution of the São Francisco craton (eastern South America) reveals that the most likely scenario is Paleoarchean uranium enrichment of carbonado, followed by Mesoproterozoic uranium dissolution. Under all possible scenarios, the carbonado radiation damage history requires U mobilization in the Mesoarchean or late Paleoarchean. This is consistent with recent studies of South Africa and India Mesoarchean paleosols, which also show evidence for local oxygen activity greater than that of the Archean atmosphere and ocean. While those studies rely on whole-rock trace element and transition metal stable isotope measurements, this combination of crystallographic defects, sedimentary geochronology, and radiogenic isotopes supports the same conclusions of nonmarine, near-surface Archean oxygen enhancement.

Tuesday, June 28, 2016

A new approach to gas exploration has discovered a huge helium gas field, which could address the increasingly critical shortage of this vital yet rare element.

Helium doesn't just make your voice squeaky - it is critical to many things we take for granted, including MRI scanners in medicine, welding, industrial leak detection and nuclear energy. However, known reserves are quickly running out. Until now helium has never been found intentionally - being accidentally discovered in small quantities during oil and gas drilling.

Now, a research group from Oxford and Durham universities, working with Helium One, a helium exploration company headquartered in Norway, has developed a brand new exploration approach. The first use of this method has resulted in the discovery of a world-class helium gas field in Tanzania.

The Grand Canyon on Earth might feel a little inadequate if it ever learns about Argo Chasma on Pluto's moon Charon. Charon is home to a canyon 185 miles (300 kilometers) long and up to 5.5 miles (9 kilometers) deep in places. NASA says Argo Chasma also has one of the tallest known cliff faces in the entire solar system.

Scientists are working with images and data from the New Horizons spacecraft, which launched in 2006 and reached dwarf planet Pluto in 2015. Compared to the Grand Canyon in the US, Argo Chasma is five times deeper and 150 miles (240 kilometers) longer. Imagine the sheer terror of looking down if someone ever builds an Argo Chasma Skywalk with a glass floor.

The origin of the martian methane is still poorly understood. A plausible explanation is that methane could have been produced either by hydrothermal alteration of basaltic crust or by serpentinization of ultramafic rocks producing hydrogen and reducing crustal carbon into methane. Once formed, methane storage on Mars is commonly associated with the presence of hidden clathrate reservoirs. Here, we alternatively suggest that chabazite and clinoptilolite, which belong to the family of zeolites, may form a plausible storage reservoir of methane in the martian subsurface. Because of the existence of many volcanic terrains, zeolites are expected to be widespread on Mars and their Global Equivalent Layer may range up to more than ∼1 km, according to the most optimistic estimates. If the martian methane present in chabazite and clinoptilolite is directly sourced from an abiotic source in the subsurface, the destabilization of a localized layer of a few millimeters per year may be sufficient to explain the current observations. The sporadic release of methane from these zeolites requires that they also remained isolated from the atmosphere during its evolution. The methane release over the ages could be due to several mechanisms such as impacts, seismic activity or erosion. If the methane outgassing from excavated chabazite and/or clinoptilolite prevails on Mars, then the presence of these zeolites around Gale Crater could explain the variation of methane level observed by Mars Science Laboratory.

A turbine-based combined cycle (TBCC) propulsion system to enable routine hypersonic flight by a vehicle that can take-off and land from a runway is back on the agenda at the Defense Advanced Research Projects Agency (DARPA) after a five-year hiatus.

The experimenting agency has set a “proposers day” on 13-14 July for potential bidders of the Advanced Full Range Engine (AFRE) programme, which is scheduled to launch as a new-start effort in Fiscal 2017.

Combining a turbine engine with a ramjet in the same vehicle has been a dream for the aerospace industry since the early 1950s, when the US Air Force proposed adapting Republic’s concept for the XF-103 fighter with a ramjet to intercept Soviet bombers at speeds up to Mach 5.

But TBCC concepts are limited by a propulsion gap between the Mach 2.5 top speed of a turbine engine and the Mach 3-3.5 minimum speed for a ramjet engine.

In 2009, DARPA attempted to bridge that gap with a high-speed turbine and a low-speed ramjet under the Mode Transition (MoTr) programme, but the project was cancelled two years later. By 2013, Lockheed Martin’s Skunk Works organisation appeared to lobby for a revival of the research effort by releasing a concept for a Mach 6.0-capable SR-72 for high-speed surveillance missions, which was based on a similar TBCC propulsion system.

The AFRE programme now seeks to pick up where MoTr left off, leading to a ground demonstration of a fully integrated propulsion system capable of taking-off from a runway and accelerating beyond Mach 5. The system will include an off-the-shelf turbine engine and a dual mode ramjet/scramjet capable of operating with subsonic or supersonic airflows. Both engines share a common inlet and exhaust nozzle, but transition from turbine to ramjet power at a certain speed over Mach 2.5.

Chew on this: rice farming is a far older practice than we knew. In fact, the oldest evidence of domesticated rice has just been found in China, and it's about 9,000 years old.

The discovery, made by a team of archaeologists that includes University of Toronto Mississauga professor Gary Crawford, sheds new light on the origins of rice domestication and on the history of human agricultural practices.

"Today, rice is one of most important grains in the world's economy, yet at one time, it was a wild plant...how did people bring rice into their world? This gives us another clue about how humans became farmers," says Crawford, an anthropological archaeologist who studies the relationships between people and plants in prehistory.

Our knowledge of Cretaceous plumage is limited by the fossil record itself: compression fossils surrounding skeletons lack the finest morphological details and seldom preserve visible traces of colour, while discoveries in amber have been disassociated from their source animals. Here we report the osteology, plumage and pterylosis of two exceptionally preserved theropod wings from Burmese amber, with vestiges of soft tissues. The extremely small size and osteological development of the wings, combined with their digit proportions, strongly suggests that the remains represent precocial hatchlings of enantiornithine birds. These specimens demonstrate that the plumage types associated with modern birds were present within single individuals of Enantiornithes by the Cenomanian (99 million years ago), providing insights into plumage arrangement and microstructure alongside immature skeletal remains. This finding brings new detail to our understanding of infrequently preserved juveniles, including the first concrete examples of follicles, feather tracts and apteria in Cretaceous avialans.

When people talk about giant azhdarchid pterosaurs (odds are most readers of this blog don't need an introduction to azhdarchids, but if you do, click here) they typically mention two taxa. The first is Quetzalcoatlus northropi, a giant Texan pterosaur discovered in the 1970s and now one of the most famous pterosaurs of all (Lawson 1975, Langston 1981). The second is Hatzegopteryx thambema, a relatively robust giant discovered in the 1990s and initially - because of its size and reinforced bone construction - thought to be a giant predatory dinosaur (see Buffetaut et al. 2003). From internet forums to TV show producers, if you want to chat about giant pterosaurs, these species are your most likely subjects.

Many readers will be aware that these aren't the only giant azhdarchids, however. The record of these animals cannot be described as extensive, but it is sufficient to indicate that they were present across most of the world and probably not particularly rare in Late Cretaceous ecosystems. But most fossils of giant azhdarchids are unnameable on account of being too fragmentary, being represented by parts of undiagnostic anatomy, or being too poorly preserved. This makes it all the more surprising that the third named giant azhdarchid doesn't get much attention: the Maastrichtian species Arambourgiania philadelphiae, known from several bones from phosphate mines in Jordan.

I'm not sure why we generally overlook this giant. Perhaps it's because Arambourgiania - 'Arambourg's giant' - is one of those old-fashioned names which works better in translation than the original Greek. It certainly doesn't sound as evocative or exotic as Quetzalcoatlus or Hatzegopteryx. Moreover, it's the least known of the three named giants, being primarily represented by a long - 620 mm - cylindrical neck vertebra, and not much else. The other named giants are not well represented either, but we have more than a handful of bones for them, and they're represented by intuitively intriguing anatomies: giant wing skeletons, bits of skull and jaw and so on. But whatever the cause, there are reasons to consider our relative neglect of Arambourgiania as unwarranted. It may not be as well-known as Quetzalcoatlus, or as immediately intriguing as Hatzegopteryx, but if you're interested in giant azhdarchids (and, hey, who isn't?) you this animal deserves your attention just as much as the other species. Here are just three reasons why.

Ediacaran sedimentary successions are noted for the preservation of microbes and microbial textures on the surfaces of sandstones and siltstones. Although microorganisms have been preserved in coarse-grained siliciclastic sand throughout geologic history, the exceptional preservation of microbes in Ediacaran sediments suggests the potential for a unique taphonomic window. Here, we identify conditions conducive to the fossilization of filamentous cyanobacteria growing in the presence of siliciclastic sand and demonstrate that the sheaths of filamentous cyanobacteria can become coated by clay minerals within days under oxic conditions. Smooth, extensive mineral coatings develop in the presence of 5.6 to 55.6 mg/L of suspended clay and 0.1 mM or greater concentrations of dissolved silica. Thus, elevated concentrations of seawater silica and the delivery of suspended clays promote microbial preservation on sandy and silty surfaces. These factors likely facilitated microbial fossilization in coarse-grained siliciclastic sand throughout the Ediacaran Period and may have also contributed to microbial fossilization in siliciclastic deposits at other times throughout Earth’s history.

The Russian Aerospace Force successfully carried out a test-firing of
the A-135 anti-ballistic missile interceptor from Sary-Shagan missile
testing site in Kazakhstan at 07:00 hours Moscow Standard Time on Jun.
21.

The New Horizons spacecraft has found evidence for geologic activity on the surface of Pluto, including extensional tectonic deformation of its water ice bedrock (see Moore et al. [2016]). One mechanism that could drive extensional tectonic activity is global surface expansion due to the partial freezing of an ocean. We use updated physical properties for Pluto and simulate its thermal evolution to understand the survival of a possible subsurface ocean. For thermal conductivities of rock less than 3 W m−1 K−1, an ocean forms and at least partially freezes, leading to recent extensional stresses in the ice shell. In scenarios where the ocean freezes and the ice shell is thicker than 260 km, ice II forms and causes global volume contractions. Since there is no evidence for recent compressional tectonic features, we argue that ice II has not formed and that Pluto's ocean has likely survived to present day.

Venus currently rotates slowly, with its spin controlled by solid-body and atmospheric thermal tides. However, conditions may have been far different 4 billion years ago, when the Sun was fainter and most of the carbon within Venus could have been in solid form, implying a low-mass atmosphere. We investigate how the obliquity would have varied for a hypothetical rapidly rotating Early Venus. The obliquity variation structure of an ensemble of hypothetical Early Venuses is simpler than that Earth would have if it lacked its large moon (Lissauer et al., 2012), having just one primary chaotic regime at high prograde obliquities. We note an unexpected long-term variability of up to ±7° for retrograde Venuses.

Orbital ATK’s continuing preparations to return its Antares rocket to flight operations has resulted in an updated preliminary launch date in the August timeframe. The launch – involving the OA-5 Cygnus spacecraft to the International Space Station (ISS) – requires static fire test data analysis to be completed, along with final trajectory shaping work.

When do laser weapons finally become real? The low-hanging fruit for a near-term application looks like it’s shooting down enemy drones before they can target US forces. Both the Army and Marines are testing vehicle-mounted “counter-UAS” (Unmanned Aerial System) lasers, while the Navy already has a bulkier model aboard the USS Ponce in the Persian Gulf.

The Marine Corps is moving towards a future in which small dispersed units can protect themselves from incoming enemy drones with laser weapons and from missiles and aircraft with Stinger missiles, with both weapons netted into a detection system and mounted atop Humvees, Joint Light Tactical Vehicles and other combat vehicles.

The Navy is “fully committed” to developing and fielding advanced directed energy weapons to deal with emerging threats and to reduce the cost per shot, the Navy’s number two officer said today.

“We need to push technology forward” and do it faster than historic advances in fielding new weapons capabilities, Vice Chief of Naval Operations Adm. William Moran said at the Directed Energy Summit, cohosted by Booz Allen Hamilton and the Center for Strategic and Budgetary Assessment.

Moran noted that the Navy had “already authorized a defensive weapon” and deployed it, citing the laser system mounted on the USS Ponce (AFSB(I)-15), which is on station in the U.S. Central Command theater.

The 30 kilowatt solid-state XN-1 laser on Ponce has been authorized for use as a defensive weapon, he said. The Navy “will field a 100-kilowatt system in the near future,” he added.

Using genetic markers, researchers have for the first time shown how cultivating a specific crop led to the expansion of a pollinator species. In this case, the researchers found that the spread of a bee species in pre-Columbian Central and North America was tied to the spread of squash agriculture.

"We wanted to understand what happens when the range of a bee expands," says Margarita López-Uribe, a postdoctoral researcher at North Carolina State University and lead author of a paper describing the work. "What does that mean for its genetic variability? And if the genetic variability declines, does that harm the viability of the species?"

To explore these questions, researchers looked at the squash bee (Peponapis pruinosa), which is indigenous to what is now central Mexico and the southwestern United States. Squash bees are specialists, collecting pollen solely from the flowers of plants in the genus Cucurbita, such as squash, zucchini and pumpkins.

Before contact with Europeans, native American peoples had begun cultivating Cucurbita crops. Over time, these agricultural practices spread to the north and east.

To find out, researchers looked at DNA from squash bee individuals, collected from throughout the species' range. P. pruinosa can now be found from southern Mexico to California and Idaho in the west, and from Georgia in the southeast to Quebec in the north.

By assessing genetic markers in each bee's DNA, the researchers could identify genetic signatures associated with when and where the species expanded.

Recent work on new anthracothere (Mammalia, Artiodactyla) specimens from the Jebel Qatrani Formation, early Oligocene, Fayum, Egypt, has revealed the presence of a new genus. Nabotherium new genus is described on the basis of a partial skull, several mandibular and maxillary specimens, and isolated teeth. The new genus exhibits a distinctive combination of features not seen in other Paleogene anthracotheres. The most noticeable characteristics of the new genus include the presence of large and well-developed upper and lower canines, caniniform third incisors, the presence of only a short diastema between the canine and first premolar, and broad, bunodont cheek teeth. This is in contrast to other contemporary anthracotheres, including other forms from the Fayum, which show a spatulate third incisor, a reduced canine, a much longer canine-premolar diastema, and more narrow, bunoselenodont cheek teeth. The presence of a relatively short rostrum with closely packed incisors, low-crowned and simple premolars, and low-crowned, bunodont molars indicates that members of the new genus would have been more efficient at crushing foods than slicing vegetation, and suggests a more varied herbivorous and frugivorous diet than was favored by other, more bunoselenodont Fayum anthracotheres.

So we ought to expect a new Scottish Referendum soon and I suspect Scotland to become an independent nation. Some are saying Northern Ireland is talking seceding as well.

I have to wonder if we have the political classes completely misreading the public, here, in Britain and abroad, because their beliefs have become so strong as to place them into an echo chamber. The world might have shifted underneath us and many might be in denial. It makes me rather worried for November.

Well, my brit friends, you can always join the US. Heck, you could even get a William Windsor, POTUS, if he were willing to abdicate. He seems far more capable than at least one of the twits in our presidential race right now.

The first nearly complete and articulated manus of the ground sloth Mylodon darwinii, from the upper Pleistocene of Argentina, is described. It shares similarities with Mylodonopsis ibseni from Brazil, including a cuneiform with a distinct pisiform facet, an obliquely concave ulnar facet, and a prominent distolateral process, as well as a gracile metacarpal III. It shares a flattened pisiform with Glossotherium robustum. The trapezoid is unique in the obliquely elongate proportions of its dorsal surface. Shapes of the articular facets indicate different functions in digits II and III, with the former having a greater range of motion and the latter greater stability at the joints. Clear arboreal or fossorial adaptations are absent. A phylogenetic analysis recovered M. darwinii as closely related to M. ibseni and agrees with larger phylogenetic analyses of sloths based on craniomandibular evidence. Our data support more than two mylodontine dispersal events to North America.

The Raipur Group of the Chattisgarh Basin preserves two major Late Mesoproterozoic carbonate platforms. The lower platform is about 490-m thick, separated from the upper platform (~ 670 m thick) by a 500-m thick calcareous shale. Carbonate strata cover almost 40% of the Chattisgarh Basin outcrop and represent two major platform types: a) a non-stromatolitic ramp (the Charmuria/Sarangarh Limestone) and b) a platform developed chiefly in the intertidal to shallow subtidal environment with prolific growth of stromatolites (the Chandi/Saradih Limestone). The first platform consists primarily of the black Timarlaga limestone that is locally replaced by early diagenetic dolomite. This carbonate platform experienced strong storm waves and was subsequently drowned by a major transgression, during which extensive black limestone–marl rhythmite was deposited, followed by deposition of the Gunderdehi Shale. The carbonate factory was later re-established with development of an extensive stromatolite-dominated Charmuria/Sarangarh platform that ranged from restricted embayment to open-marine conditions. Sea-level change played a major role in controlling the broad facies pattern and platform evolution. The δ13C signatures of the Chattisgarh limestones, falling within a relatively narrow range (0 to + 4‰) are typical for Upper Mesoproterozoic carbonate rocks. δ18O values, however, have a greater range (− 5.7 to − 13.3‰) indicating significant diagenetic alteration of some samples. Likely dysoxic or anoxic conditions prevailed during deposition of the black Timarlaga limestone and well-oxygenated conditions during deposition of the Gunderdehi Shale and Saradih/Chandi stromatolite. The lack of 17β,21α (moretanes) and high Tmax values suggest mature organic matter in the non-stromatolitic ramp. A paucity of diagnostic eukaryotic steroids indicates that algae were rare in the Chattisgarh Basin. A high content of hopanes supports a generally bacterially-dominated Proterozoic ocean in which various stromatolites flourished.

Thursday, June 23, 2016

It’s a major component of solid rocket propellants. It allows water to exist as liquid on Mars, despite atmospheric pressure at the Martian surface being roughly 0.6 percent that on Earth. It also can be broken down to release oxygen that astronauts and future colonists in a Mars settlement could breathe.

It’s called perchlorate and it’s abundant on Mars –10,000 times more abundant in Martian dirt than in soils and sands of Earth. That may sound like a good thing, considering the useful properties of perchlorate, but there’s also a flip side.

Being a negative ion, perchlorate (ClO4–) forms various salts, but it has detrimental health effects. Potassium perchlorate is used as a drug to treat certain forms of hyperthyroidism (overactive thyroid). But exposure to environmental perchlorate causes the opposite of hyperthyroidism, namely hypothyroidism — an underactive thyroid.

United Launch Alliance says it has identified and resolved the problem on its most recent Atlas 5 launch, a March 22 flight for Orbital ATK that successfully delivered the unmanned Cygnus space station resupply vehicle to orbit.

In a statement June 15, the Denver-based company said an “unexpected shift in fuel pressure differential” across a mixture ratio control valve in the RD-180 engine, nearly four minutes after liftoff, caused the engine to run oxidizer-rich.

That depleted the supply of liquid oxygen and shut down the engine prematurely, even though there was still “significant fuel” left on the first stage. Atlas 5’s Centaur upper stage compensated for the first stage performance shortfall with an extended burn, delivering Cygnus to its intended orbit “well within the required accuracy.”

As difficult as any rocket is the engineering required to created powered armor that carries its own weight without burdening the wearer, an military exoskeleton like Heinlein’s Mobile Infantry or Marvel’s Iron Man. The Special Operations Command is researching such a system, TALOS, but when asked about its applicability to the rest of the Army, Allyn was skeptical.

“Currently, in the conventional force, I doubt we could afford it in the near term,” at least on any large scale, said Allyn. So are you at least interested? “I wouldn’t say as yet I’m interested because I try not to get interested in things I cant afford,” Allyn said with a smile. “I don’t go to the Jaguar and Mercedes dealerships.”

Of course, if the Army got more money, it could make different choices. Currently the service is “mortgaging” long-term modernization to pay for near-term readiness, Allyn said, which puts a damper on all new technologies. “The way out obviously is increased topline — and there’s not a likelihood of receiving that,” Allyn said.

Giant Ice Age species including elephant-sized sloths and powerful sabre-toothed cats that once roamed the windswept plains of Patagonia, southern South America, were finally felled by a perfect storm of a rapidly warming climate and humans, a new study has shown.

Research led by the Australian Centre for Ancient DNA (ACAD) at the University of Adelaide, published today in Science Advances, has revealed that it was only when the climate warmed, long after humans first arrived in Patagonia, did the megafauna suddenly die off around 12,300 years ago.

The timing and cause of rapid extinctions of the megafauna has remained a mystery for centuries.

"Patagonia turns out to be the Rosetta Stone - it shows that human colonisation didn't immediately result in extinctions, but only as long as it stayed cold," says study leader Professor Alan Cooper, ACAD Director. "Instead, more than 1000 years of human occupation passed before a rapid warming event occurred, and then the megafauna were extinct within a hundred years."

We report three isolated humeri of small-sized parareptiles, which represent two different taxa, from the lower Keuper (Erfurt Formation) of Germany. They constitute the first definitive evidence of parareptiles in the lower Keuper. The specimens represent the first records of an owenettid procolophonian (aff. Barasaurus) from Europe and of a putative gracile-built procolophonid. This indicates the coexistence in the Middle Triassic of Germany of two procolophonian lineages that first appeared in the fossil record in the late Permian and survived the Permian–Triassic extinction. Although based on isolated limb bones, they highlight the taxonomic diversity of the still poorly known tetrapod assemblage of the lower Keuper in southwestern Germany.

Precipitation of cap carbonate lithologies is a key feature of Cryogenian global glaciations. Negative carbonate carbon isotopic compositions (δ13Ccarb) of these cap carbonates have been variably interpreted as massive drawdown of atmospheric CO2 via extensive continental chemical weathering, methane oxidation, or postglacial upwelling. Each of these interpretations argues a non-steady state of carbon cycle in the aftermath of Marinoan global glaciation. To further explore the postglacial marine carbon cycle, we measured δ13Ccarb of cap carbonates from six localities in the Yangtze Platform, South China. The studied cap carbonates were deposited in a variety of sedimentary environments, ranging from the open shelf, slope, to basin facies. Cap carbonates deposited in different environments show distinct stratigraphic trends of δ13Ccarb. In the open shelf, δ13Ccarb profile of the Songlin section remains almost constant (-3 to -4‰), while the δ13Ccarb of the Jiulongwan section records a negative excursion, decreasing from -3.5‰ to -7‰. δ13Ccarb of cap carbonates deposited in the slope environment does not show stable stratigraphic trend. In the basin environment, δ13Ccarb demonstrates a sharp decline in the middle part of cap carbonates to the nadir value of ∼ -11‰. The negative δ13Ccarb excursion is best interpreted in terms of oxidation of dissolved organic carbon (DOC), thus recording a pulse of ocean oxidation during cap carbonate precipitation. Clearly absence of negative δ13Ccarb excursion in all slope and most open shelf sections may imply that such oxidation event was not ubiquitous in the Yangtze Platform. We speculate that the renewed thermohaline circulation during deglaciation brought oxic surface water into ocean interior, which oxidized the basin environment of the Yangtze Platform. However, the deglacial thermohaline circulation was not strong enough to cause complete oxidation of the ocean. The sporadic oxidation in the open shelf, on the other hand, might result from the terrestrial influx of oxidant from postglacial continental weathering. Our study suggests that ocean oxidation, though sporadic, might have occurred during cap carbonate precipitation, and predated the first appearance of putative animal embryos.

Turkish President Recep Tayyip Erdoğan has stressed the significance of the defense industry, saying that Turkey will soon start producing an aircraft carrier after an Anatolian ship, which is a sub type of amphibious vehicle.

Erdoğan's remarks were made in his speech at a launching ceremony of the Istanbul Naval Shipyard.

"There isn't any obstacle to producing our own aircraft carrier. It is possible with this determined government and state," said Erdoğan.

Many of us in India dream of becoming astronauts who reach out for the stars when we are young, despite India not having a human space program. As we grow up, we start to live up to the expectations of our society and make our ends meet by not chasing such wild dreams, but rather by shaping our talent to contribute to other opportunities by taking jobs in the government, private sector, or academia. There are some who achieve their dreams of working in the space sector and join the Indian Space Research Organisation (ISRO) as scientists and engineers.

However, there are some who continue to dream about reaching for the stars, much like they did in their childhood, and take risks to chase those dreams. Over the last few years we are witnessing the emergence of NewSpace in India, with a vision to build world-class enterprises that do business based on developing space assets. Many of these NewSpace companies are built on the inspiration of creating a company like SpaceX in India. This is a moonshot, but one that matches the growing spirit of entrepreneurship in India. However, what makes a SpaceX?

Wednesday, June 22, 2016

Observations of Pluto's surface made by the New Horizons spacecraft indicates present-day nitrogen ice glaciation in and around the basin known as Sputnik Planum. Motivated by these observations, we have developed an evolutionary glacial flow model of solid nitrogen ice taking into account its published thermophysical and rheologies properties. This model assumes that glacial ice layers flow laminarly and have low aspect ratios which permits a vertically integrated mathematical formulation. We assess the conditions for the validity of laminar nitrogen ice motion by revisiting the problem of the onset of solid-state buoyant convection of nitrogen ice for a variety of bottom thermal boundary conditions. Subject to uncertainties in nitrogen ice rheology, nitrogen ice layers are estimated to flow laminarly for thicknesses less than 400-1000 meters. The resulting mass-flux formulation for when the nitrogen ice flows as a laminar dry glacier is characterized by an Arrhenius-Glen functional form. The flow model developed is used here to qualitatively answer some questions motivated by observed glacial flow features found on Sputnik Planum. We find that the wavy transverse dark features found along the northern shoreline of Sputnik Planum may be a transitory imprint of shallow topography just beneath the ice surface suggesting the possibility that a major shoreward flow event happened relatively recently within the last few hundred years. Model results also support the interpretation that the prominent darkened features resembling flow lobes observed along the eastern shoreline of the Sputnik Planum basin may be a result of wet nitrogen glacial ice flowing into the basin from the pitted highlands of eastern Tombaugh Regio.

Venus has an "electric wind" strong enough to remove the components of water from its upper atmosphere, which may have played a significant role in stripping Earth's twin planet of its oceans, according to new results from ESA's (European Space Agency) Venus Express mission by NASA-funded researchers.

"It's amazing, shocking," said Glyn Collinson, a scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "We never dreamt an electric wind could be so powerful that it can suck oxygen right out of an atmosphere into space. This is something that has to be on the checklist when we go looking for habitable planets around other stars." Collinson is lead author of a paper about this research published June 20, 2016, in the journal Geophysical Research Letters.